but i can't to insert it, because beetwen glBegin(GL_TRIANGLE_STRIP) and glEnd() it does not work. And i can't write glBegin(GL_TRIANGLE_STRIP), glEnd() inside for cycle, because it does not work there.

Sure it doesn't, because glEnd finishes your primitive, and you render triangle strips which require at least three vertices to produce a primitive, otherwise it doesn't product anything, and you only passed two.

When you do glBegin it won't magically catch up from where you left.

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